1. Technical Field
The present invention relates to ink, an ink cartridge, an inkjet recording device, and a copolymer.
2. Background Art
Inkjet recording methods are advantageous in comparison with other recording methods in that the process is simple, full colorization is easy, and high resolution images can be obtained by a device having a simple configuration. For this reason, the inkjet recording is widely diffusing from home use to office use, commercial printing, and industrial printing.
For office use, typically plain paper is used as a recording medium and high image density is demanded.
In addition, in the commercial printing and industrial printing, other kinds of paper such as coated paper and art paper are also used.
In such an inkjet recording method, mostly aqueous ink using water soluble dye as a colorant is used. However, its water resistance and light resistance are inferior, which accelerates development of a pigment ink using a water insoluble pigment in place of the water soluble dye.
In general, when images are printed on plain paper using pigment ink, the pigment ink permeates into the paper, so that the pigment density on the surface decreases, thereby lowering the image density. If the pigment concentration in the pigment ink increases, the image density increases. However, the pigment ink becomes viscous, thereby degrading discharging stability of the ink.